A new approach for antigen presentation and polyvalent vaccines is proposed. Experiments are designed to test the idea of combining the gene of a second immunogen with that of hepatitis B surface antigen (HBsAg) such that the second imunogen is assembled into, and presented on the surface of the HBsAg particle. These engineered genes are expressed as particles with high efficiency by transformed yeast or mammalian cells. Using hybrid HBsAg-HSV-1gD particles as a model we propose: a) To develop a standard method for purification of the hybrid antigen based on the properties of the HBsAg particle, b) to test in animals the ability of the hybrid particle to induce anti- bodies against both antigens, and c) to test these particles as a vaccine in animals for protection aginst a challenge with the corresponding infectious agent. Once proven successfully, this strategy has wide general application for the manufacture of safe and efficacious vaccines for human use.